build: Bump Bazel to 3.7.0

[sunjayBhatia]

Commit Message: Bump Bazel to 3.7.0
Additional Description: Build container bumps MSVC toolchain for Windows, helps us move forward to enable clang-cl which requires LLVM 11.0.0 (requires a bug fix backported to Bazel 3.7.1 and in 4.0.0)
Risk Level: Low
Testing: N/A
Docs Changes: N/A
Release Notes: N/A
Platform Specific Features: N/A

[repokitteh-read-only]

CC @envoyproxy/dependency-shepherds: Your approval is needed for changes made to (bazel/.*repos.*\.bzl)|(bazel/dependency_imports\.bzl)|(api/bazel/.*\.bzl)|(.*/requirements\.txt)|(.*\.patch).

🐱

Caused by: #14123 was opened by sunjayBhatia.

see: more, trace.

[moderation]

/lgtm deps

[sunjayBhatia]

coverage differences in test/common/network

master: https://storage.googleapis.com/envoy-postsubmit/master/coverage/source/common/network/socket_impl.cc.gcov.html

PR: https://storage.googleapis.com/envoy-pr/9f7beaf/coverage/source/common/network/socket_impl.cc.gcov.html

[lizan]

coverage differences in test/common/network

master: https://storage.googleapis.com/envoy-postsubmit/master/coverage/source/common/network/socket_impl.cc.gcov.html

PR: https://storage.googleapis.com/envoy-pr/9f7beaf/coverage/source/common/network/socket_impl.cc.gcov.html

I've seen same in different PR as well, might not related to the bump but might be some flakes (and being cached)

[wrowe]

@sunjayBhatia is taking the entire week, but I'm available to tweak commits, or you can do so yourself.

My 2c, let's take this if it is convenient before Tuesday, just to have greater confidence in the 3.7.1 bump.

[lizan]

all fuzz_coverage tests are failing and it's obviously broken, so we need to fix that and I don't think it will be fixed in 3.7.1 either.

[wrowe]

we need to fix that and I don't think it will be fixed in 3.7.1 either

Have you identified this as bazel's or envoy's defect, @lizan? There's still a window today to note the regression at bazelbuild/bazel#12188 if this represents a 3.6.0 regression.

[sunjayBhatia]

Bumps to Bazel 3.7+ are blocked on bazelbuild/bazel#12545

[sunjayBhatia]

closing in favor of #14134, though we will need a 3.7.2 to fix the regression reported in bazelbuild/bazel#12545